[PATCH v2 00/12] x86: major paravirt cleanup

From: Juergen Gross via Virtualization <virtualization@lists.linux-foundation.org>
To: xen-devel@lists.xenproject.org, x86@kernel.org,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	linux-hyperv@vger.kernel.org, kvm@vger.kernel.org
Cc: Juri Lelli <juri.lelli@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	peterz@infradead.org, Ben Segall <bsegall@google.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Wei Liu <wei.liu@kernel.org>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Joerg Roedel <joro@8bytes.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	"VMware, Inc." <pv-drivers@vmware.com>,
	Ingo Molnar <mingo@redhat.com>, Mel Gorman <mgorman@suse.de>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Borislav Petkov <bp@alien8.de>,
	luto@kernel.org, Vincent Guittot <vincent.guittot@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Jim Mattson <jmattson@google.com>,
	Juergen Gross <jgross@suse.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: [PATCH v2 00/12] x86: major paravirt cleanup
Date: Fri, 20 Nov 2020 12:46:18 +0100	[thread overview]
Message-ID: <20201120114630.13552-1-jgross@suse.com> (raw)

This is a major cleanup of the paravirt infrastructure aiming at
eliminating all custom code patching via paravirt patching.

This is achieved by using ALTERNATIVE instead, leading to the ability
to give objtool access to the patched in instructions.

In order to remove most of the 32-bit special handling from pvops the
time related operations are switched to use static_call() instead.

At the end of this series all paravirt patching has to do is to
replace indirect calls with direct ones. In a further step this could
be switched to static_call(), too, but that would require a major
header file disentangling.

Note that an updated objtool is needed for this series, as otherwise
lots of warnings due to alternative instructions modifying the stack
will be issued during the build.

Changes in V2:
- added patches 5-12

Juergen Gross (12):
  x86/xen: use specific Xen pv interrupt entry for MCE
  x86/xen: use specific Xen pv interrupt entry for DF
  x86/pv: switch SWAPGS to ALTERNATIVE
  x86/xen: drop USERGS_SYSRET64 paravirt call
  x86: rework arch_local_irq_restore() to not use popf
  x86/paravirt: switch time pvops functions to use static_call()
  x86: add new features for paravirt patching
  x86/paravirt: remove no longer needed 32-bit pvops cruft
  x86/paravirt: switch iret pvops to ALTERNATIVE
  x86/paravirt: add new macros PVOP_ALT* supporting pvops in
    ALTERNATIVEs
  x86/paravirt: switch functions with custom code to ALTERNATIVE
  x86/paravirt: have only one paravirt patch function

 arch/x86/Kconfig                      |   1 +
 arch/x86/entry/entry_32.S             |   4 +-
 arch/x86/entry/entry_64.S             |  32 ++--
 arch/x86/include/asm/cpufeatures.h    |   3 +
 arch/x86/include/asm/idtentry.h       |   6 +
 arch/x86/include/asm/irqflags.h       |  51 ++----
 arch/x86/include/asm/mshyperv.h       |  11 --
 arch/x86/include/asm/paravirt.h       | 170 ++++++--------------
 arch/x86/include/asm/paravirt_time.h  |  38 +++++
 arch/x86/include/asm/paravirt_types.h | 222 ++++++++++++--------------
 arch/x86/kernel/Makefile              |   3 +-
 arch/x86/kernel/alternative.c         |  30 +++-
 arch/x86/kernel/asm-offsets.c         |   8 -
 arch/x86/kernel/asm-offsets_64.c      |   3 -
 arch/x86/kernel/cpu/vmware.c          |   5 +-
 arch/x86/kernel/head_64.S             |   2 -
 arch/x86/kernel/irqflags.S            |  11 --
 arch/x86/kernel/kvm.c                 |   3 +-
 arch/x86/kernel/kvmclock.c            |   3 +-
 arch/x86/kernel/paravirt.c            |  70 +++-----
 arch/x86/kernel/paravirt_patch.c      | 109 -------------
 arch/x86/kernel/tsc.c                 |   3 +-
 arch/x86/xen/enlighten_pv.c           |  36 +++--
 arch/x86/xen/irq.c                    |  23 ---
 arch/x86/xen/time.c                   |  12 +-
 arch/x86/xen/xen-asm.S                |  52 +-----
 arch/x86/xen/xen-ops.h                |   3 -
 drivers/clocksource/hyperv_timer.c    |   5 +-
 drivers/xen/time.c                    |   3 +-
 kernel/sched/sched.h                  |   1 +
 30 files changed, 325 insertions(+), 598 deletions(-)
 create mode 100644 arch/x86/include/asm/paravirt_time.h
 delete mode 100644 arch/x86/kernel/paravirt_patch.c

-- 
2.26.2

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